Supported files and troubleshooting
Which schematic PDFs analyze well, and what to check and how to re-export when a file won't open or the connections look wrong.
PDFs that work well
Schematic Viewer reads the lines (vector paths) and text (text layer) in a PDF to infer connections, so PDFs exported directly from a schematic program work best.
| Schematic program | Status | Notes |
|---|---|---|
| KiCad (5–8) | Works well | Export in colour: the wire colour separates wires from symbol lines and gives the best accuracy. |
| Altium Designer | Works well | Smart PDF exports carry a netlist in the PDF bookmarks, which is used to correct the connections. |
| Eagle / Fusion Electronics | Mostly works | PDFs that draw their lettering as lines limit name search. |
| OrCAD Capture | Mostly works | Often black and white, but the link data inside the PDF (net labels, part boxes) is used to tell labels and parts apart. |
| Others (EasyEDA, redrawn documentation schematics …) | Depends on the drawing | Usually fine when wires are straight lines and text is real text. |
In short, analysis works best when the PDF:
- was exported from a program, not scanned or photographed;
- contains its lettering as text, not as lines (if you can drag-select words in a PDF reader, it is text);
- is in colour where possible (wires in a different colour from symbols improve accuracy);
- has no password.
What each message means
"Only PDF files can be opened"
The file is not a PDF (an image, an archive, a CAD source file …). Export a PDF from your schematic program and open that, and check that the file name ends in .pdf.
"Password-protected PDFs can't be opened"
A browser cannot read a PDF protected with an open password. If you know the password, open it in a PDF reader and save a copy without the password (or use "Print → Save as PDF"), then open the copy. For company documents, check your security policy first.
"Unable to read this PDF"
Usually the file is damaged or was opened before its download finished. Download the original again; if that fails, export the PDF again from your schematic program. Very old browsers can also cause this — a current Chrome, Edge, Safari or Firefox is recommended.
"This PDF has no line or text data"
The PDF is a scan or a screenshot saved as PDF. You can still view the drawing, but its lines and letters are pictures, so the connections can't be analyzed. Export the PDF again from the original schematic program.
It opens, but the result looks wrong
The net list is empty or has few names
The PDF draws its lettering as lines instead of text. Names can't be read, so the net list and name search stay empty, but clicking a wire still highlights its connections. For OrCAD PDFs, the part data inside the PDF still provides the parts list and part search. Look for an export option that keeps fonts as text (for example "use TrueType fonts" or "don't convert text to outlines") and export again.
Different nets appear merged
In black-and-white PDFs wires and symbols share one colour, so a part outline or a pin line can be mistaken for a wire. Exporting in colour fixes most cases. If it keeps happening with a drawing, tell us through the contact page — a public example showing the same problem helps us fix it faster than a private drawing.
Some labels with the same name are not connected
A label slightly away from its wire, or overlapping a pin name, may not be recognized as a label. Search still finds every occurrence, so search for the name to check.
A part has no value
Values written far from the reference or in a different direction may not be grouped with it. Click the part and check the drawing. See Finding parts in a schematic PDF.
The drawing stays grey or looks rough
"Rendering drawing" is shown while the PDF is being drawn. If it never appears, the browser cannot draw the PDF and an outline drawing from the analysis is shown instead. Please update your browser.
Multi-page schematics
Each page is analyzed on its own, and nets with the same name are combined in the list. Pages containing the selected net are marked with a dot on the page numbers, and the label buttons move across pages. Connections that cross pages without a name (hierarchical sheet ports, for example) are not followed yet.